VLBI monitoring of the complex jet of Cygnus X-3 during the January 1991 outburst

We report on high sensitivity VLBI observations of Cygnus X-3 at 6 cm wavelength on four consecutive days during the large radio flaring event in January, 1991. Both total flux density evolution and visibility amplitudes indicate the presence of a complex jet. The superposition of flares however excludes unique modelling of the source structure and evolution. The minimum consistent interpretation requires at least five components of scattering size 16 milliarc-seconds (mas), resulting in a linear structure with a position angle of 180(o) with an uncertainty estimate of +/- 10(o) .